Apparatus and method for treating a fracture of a bone

ABSTRACT

An apparatus and method for treating a fracture of a bone is provided. A bone suture assembly includes a first bone plate positioned proximate to the bone. A suture is positioned through the first bone plate and across the fracture of the bone to thereby stabilize the fracture. A method of treating a fracture of a bone includes positioning at least one suture anchor proximate to the bone and positioning at least one bone plate between at least one suture anchor and the bone. The method also includes moving at least one suture across the fracture of the bone and through at least one bone plate, attaching at least one suture to at least one suture anchor, and tensioning at least one suture to stabilize the fracture of the bone.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.09/835,473 filed Apr. 16, 2001 now U.S. Pat. No. 6,638,279. Theaforementioned application Ser. No. 09/835,473 is itself a continuationof U.S. patent application Ser. No. 09/532,942 filed Mar. 22, 2000, nowU.S. Pat. No. 6,238,395. The aforementioned application Ser. No.09/532,942 is itself a continuation of U.S. patent application Ser. No.09/363,707 filed Jul. 29, 1999, now U.S. Pat. No. 6,045,551. Theaforementioned application Ser. No. 09/363,707 is itself acontinuation-in-part of U.S. patent application Ser. No. 09/323,488filed Jun. 1, 1999, now U.S. Pat. No. 6,117,160. The aforementionedapplication Ser. No. 09/323,488 is itself a continuation of U.S. patentapplication Ser. No. 09/019,977 filed Feb. 6, 1998, now U.S. Pat. No.5,921,986. The benefit of the earlier filing dates of the aforementionedapplications and patents is claimed.

BACKGROUND OF THE INVENTION

The present invention relates to a new and improved method and apparatusfor securing sections of a fractured bone and/or securing body tissue tobone.

When a bone is broken or fractured, it is necessary to press sections ofthe bone on opposite sides of the fracture together in order to promotehealing of the bone. Bone screws have been used with or without metalplates to hold the sections of the fractured bone against movementrelative to each other. In addition, it has been suggested that avulsionfractures could be treated by using wire sutures between sections ofbone in a matter similar to that disclosed in U.S. Pat. No. 5,474,554.It has also been suggested that an anchor could be retained in a bone isa manner disclosed in U.S. Pat. Nos. 5,527,343 and 5,534,012.

SUMMARY OF THE INVENTION

The present invention relates to a method of securing sections of afractured bone. Sections of a fractured bone are held against movementrelative to each other.

In accordance with one aspect of the present invention, there isprovided a bone suture assembly for treating a fracture of a bone. Thebone suture assembly includes a first bone plate positioned proximate tothe bone and a suture positioned through the first bone plate and acrossthe fracture of the bone to thereby stabilize the fracture. The sutureassembly may include a second bone plate positioned proximate to thebone generally opposite the first bone plate. The suture may bepositioned through the second bone plate to stabilize the fracture. Thesuture assembly may also include a passage through the bone and acrossthe fracture, wherein the suture is disposed within the passage. Thepassage may be nonlinear and may include a tubular member. The suturemay be disposed within the tubular member.

Furthermore, the bone suture assembly may include at least one fastenerto hold the first bone plate to the bone. At least one fastener mayextend across the fracture of the bone and may extend through the boneand through the second bone plate. At least one fastener may alsoinclude a screw and nut. Additionally, the suture assembly may include atubular member in the bone positioned across the fracture, and thesuture may be disposed within the tubular member. The tubular member maybe packed with bone particles or bone osteoinductive protein.

In accordance with another aspect of the present invention, the bonesuture assembly includes a first suture anchor positioned proximate tothe bone, a first bone plate positioned between the first suture anchorand the bone, and a suture positioned across the fracture of the bone tostabilize the fracture. The suture has a first end portion disposedthrough the bone plate and attached to the first suture anchor. Thesuture assembly may also include a second suture anchor positionedproximate to the bone generally opposite the first suture anchor. Thesecond suture anchor may be attached to a second end portion of thesuture.

Moreover, the bone suture assembly may include a second bone platepositioned between the second suture anchor and the bone. The sutureassembly may also include a passage through the bone and across thefracture, wherein the suture is disposed within the passage. In thepresent invention, the first and second suture anchors may be sutureretainers which may have deformable material to hold the sutureretainers to the suture.

In accordance with still another aspect of the present invention, amethod for treating a fracture of a bone is provided. The methodincludes positioning at least one suture anchor proximate to the bone,positioning at least one bone plate between at least one suture anchorand the bone, and moving at least one suture across the fracture of thebone and through at least one bone plate. The method also includesattaching at least one suture to at least one suture anchor andtensioning at least one suture to stabilize the fracture of the bone. Atleast one suture anchor may be a suture retainer.

In addition, the method may include fastening at least one bone plate tothe bone with at least one screw. At least one screw may have a lengthless than the diameter of the bone, and at least one screw may have alength greater than the diameter of the bone. At least one screw mayinclude at least one nut, and at least one screw may extend across thefracture of the bone.

Furthermore, the method may include forming at least one passage throughthe bone and moving at least one suture through at least one passage.Also, at least one suture attached to at least one suture anchor may bemoved through at least one passage. The method may also include changingthe orientation of at least one suture anchor from a first to a secondconfiguration thereby causing at least one suture anchor to becomeproximate to the bone and impassable through at least one passage.Finally, the method may include tensioning at least one suture betweenat least two suture anchors to stabilize the fracture of the bone.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the invention will become moreapparent upon a consideration of the following description taken inconnection with the accompanying drawings wherein:

FIG. 1 is a schematic illustration of a bone having a fracture which hasbeen treated with sutures and suture anchors;

FIG. 2 is an enlarged fragmentary schematic sectional view of a portionof the bone of FIG. 1 and illustrating the manner in which a sutureextends across the fracture and interconnects suture anchors on oppositesides of the fracture;

FIG. 3 is a schematic illustration, generally similar to FIG. 2,illustrating the manner in which a suture retainer is used to maintaintension in a suture which extends across a fracture to a suture anchor;

FIG. 4 is a schematic illustration, generally similar to FIGS. 2 and 3,illustrating the manner in which body tissue is connected with a boneusing a suture and suture anchors;

FIG. 5 is a schematic illustration, generally similar to FIGS. 2-4,illustrating the manner in which a suture extends between suture anchorsthrough a nonlinear passage;

FIG. 6 is a schematic illustration, generally similar to FIG. 5,illustrating the manner in which a suture extends between a sutureanchor and a suture retainer through a nonlinear passage;

FIG. 7 is a schematic illustration depicting a bone which has beenfractured in such a manner as to have a bone fragment connected with thebone by muscle or other fibrous tissue;

FIG. 8 is a schematic illustration depicting the manner in which thebone fragment of FIG. 7 is connected to the bone by a suture and a pairof suture anchors;

FIG. 9 is a schematic illustration depicting the manner in which a bonefragment is connected with a bone by a suture which extends between ananchor within the bone and an anchor which engages the bone fragment;

FIG. 10 is a schematic illustration, generally similar to FIGS. 2-4,illustrating in the manner in which plates and rigid fasteners are usedin association with a suture and anchors to treat a bone fracture;

FIG. 11 is a schematic illustration depicting the manner in which a thinelongated member is moved through bone and the manner in which a drillis moved along the thin elongated member to enlarge a passage formed inthe bone by the thin elongated member;

FIG. 12 is a schematic illustration depicting the manner in which ananchor is moved through a passage in the drill of FIG. 11 after the thinelongated member has been removed from the passage in the drill;

FIG. 13 is a schematic illustration, generally similar to FIG. 2,illustrating the manner in which a tubular member is positioned in apassage in the bone;

FIG. 14 is a schematic illustration, generally similar to FIG. 5,illustrating the manner in which tubular members are positioned in anonlinear passage in a bone; and

FIG. 15 is a schematic illustration, generally similar to FIG. 3,illustrating the manner in which a suture retainer is used with atubular member which is positioned in a passage in a bone.

DETAILED DESCRIPTION OF THE INVENTION

A bone 20 which has been fractured is illustrated in FIG. 1. The bone 20is divided into two sections 22 and 24 by a fracture 26. Opposite sidesurfaces 28 and 30 of the fracture 26 are pressed together by bonesuture assemblies 32.

It should be understood that the bone suture assemblies 32 may beutilized in the treatment of any one of many different types offractures. The fractures may or may not result in the formation of oneor more bone fragments. In FIG. 1, the bone suture assemblies 32 havebeen illustrated as interconnecting sections 22 and 24 of a completebone fracture of the spiral type. However, the bone suture assemblies 32could be utilized to connect a fragment of a bone to the main portion ofthe bone from which the fragment was broken off.

Each of the bone suture assemblies 32 has the same construction.However, the bone suture assemblies 32 could have differentconstructions if desired. The construction of one of the identical bonesuture assemblies 32 is illustrated in FIG. 2.

The bone suture assembly 32 (FIG. 2) includes a flexible suture 38 whichextends across the fracture 26. The suture 38 is disposed in a straightcylindrical passage 40 which extends diametrically across a generallycylindrical portion of the bone 20. The passage 40 extends through hardcompact tissue of an outer layer 42 of the bone and through spongy orcancellous bone tissue 44 which is enclosed by the hard outer layer.Although the passage 40 has a linear configuration, the passage couldhave a nonlinear configuration if desired.

The suture 38 extends between a first suture anchor 50 disposed on oneside of the fracture 26 and a second suture anchor 52 disposed on theopposite side of the fracture. Tension is maintained in the suture 38 topress the suture anchors 50 and 52 against opposite sides of the bone 20with a predetermined force. This force presses the side surfaces 28 and30 of the fracture 26 firmly together to promote healing of thefracture. If desired, buttons or other force distributing members couldbe provided between the anchors 50 and 52 and the bone 20. Body tissuecould be disposed between the anchors 50 and 52 and the bone 20.

The suture 38 and/or suture anchors 50 and 52 maybe formed of anydesired natural or artificial material. For example, the suture 38 mayformed of either a polymeric material or a metal. The suture 38 may bebiodegradable. Any known suture material may be utilized to form thesuture 38.

The suture anchors 50 and 52 have the same construction. However, theanchor 50 could have a construction which is different than theconstruction of the anchor 52. The anchor 50 has a cylindrical outerside surface 56 which extends between smooth rounded end portions 58 and60. A pair of parallel cylindrical openings 64 and 66 extenddiametrically through the anchor 50. The anchor 50 is free of sharpcorners or projections to avoid cutting or abrading of body tissuedisposed adjacent to the anchor.

The suture anchor 50 is made of a biocompatible material. Suitablematerials include stainless steel or titanium, cobalt chrome and otherbiocompatible metals. Polymeric material may also be used, suitablepolymeric materials includes polyethylene, polypropylene, andbiodegradable material such as PLA and PGA. It is believed that it maybe preferred to form the suture anchors 50 and 52 from biodegradable orbioerodible copolymers. If desired, the anchor 50 could be formed ofbody material or hydrophilic materials.

It is contemplated that the anchor 50 may have any desiredconfiguration. For example, the anchor 50 could have any one of theconfigurations disclosed in U.S. Pat. No. 5,522,846 issued Jun. 4, 1996and entitled “Suture Anchor”. Alternatively, the suture anchor 50 couldhave the configuration disclosed in U.S. Pat. No. 5,534,012 issued Jul.9, 1996 and entitled “Method and Apparatus for Anchoring a Suture”.

Although the anchor 50 may have any desired configuration, thecross-sectional size of the anchor is such as to enable the anchor to bemoved through the passage 40. In addition, the length of the anchor 50is such as to enable it to span an opening at an end of the passage 40and transmit force from the suture 38 to a substantial area on the outerlayer 42 of the bone 20. It is believed that it will be preferred toform the anchor 50 in such a manner as to eliminate any sharp corners orprojections.

In the illustrated embodiment of the invention, the anchor 50 has acylindrical configuration. This particular anchor has an axial length ofabout two millimeters and a diameter of about one millimeter. The lengthof the anchor 50 may be approximately three times the diameter of theanchor. The openings 64 and 66 have a diameter of about one-halfmillimeter.

It should be understood that the foregoing dimensions have been setforth herein for purposes of clarity of description and it iscontemplated that the size of the anchor 50 may vary as a function ofthe size of the bone being treated. Thus, relatively small anchors maybe used in association with treatment of small bones in a wrist, hand,foot or ankle of a patient. Relatively large anchors may be used inassociation with treatment of larger bones in an arm, shoulder, leg orhip of a patient. It should be understood that the bone suture assembly32 may be used in conjunction with many different bones other than thespecific bones previously mentioned.

Only a single anchor 50 or 52 has been shown at opposite ends of thepassage 40. It is contemplated that a plurality of anchors could beprovided at each end of the passage 40. For example, a pair of separateor interconnected anchors could be provided in a manner similar to thatdisclosed in the aforementioned U.S. Pat. No. 5,534,012.

In the embodiment of the invention illustrated in FIG. 2, the suture 38has a pair of limbs or sections 72 and 74 which extend through theopenings 64 and 66 in the suture anchors 50 and 52. A connector section76 interconnects the two limbs 72 and 74 of the suture 38 and engages aportion of the anchor 50. A knot 78 is formed in the opposite ends ofthe limbs 72 and 74 to interconnect the two limbs of the suture 38.

When the knot 78 is formed, a predetermined tension is present in thelimbs 72 and 74 of the suture 38. This results in the suture anchors 50and 52 being pressed firmly against the bone 20 with a predeterminedforce. This predetermined force is maintained during and after tying ofthe knot 78.

When the bone suture assembly 32 is to be used to treat the fracture 26in the bone 20, the two sections 22 and 24 of the bone are pressedtogether at the fracture 26 to align the side surfaces 28 and 30 of thefracture. A drill is then used to form the passage 40 which extendsdiametrically through the generally cylindrical bone 20. Of course, thepassage 40 could be formed by the use of a tool other than a drill. Ifdesired, the passage 40 could have a noncircular cross-sectionalconfiguration.

Once the passage 40 has been formed in the two sections 22 and 24 of thebone 20, a tubular cylindrical member is inserted into the passage 40and extends diametrically through the bone 20. The leading end of thetubular cylindrical member is aligned with a circular outlet 84 from thepassage 40. The opposite end of the tubular member is aligned with acircular inlet 86 to the passage 40. The tubular member has a thincylindrical wall which engages the sections 22 and 24 of the bone 20. Acylindrical inner side surface of the tubular member defines a passagehaving a diameter which is only slightly less than the diameter of thepassage 40.

By inserting the tubular member into the passage 40, the portions of thepassage disposed on opposite sides of the fracture 26 are maintained inalignment. The tubular member may be flexible to enable the tubularmember to be inserted into a nonlinear passage 40 through the bone 20.The tubular member may be formed of metal or a polymeric material. Ifthe tubular member is formed of a polymeric material, it may bepreferred to form the tubular member from a biodegradable or bioerodiblecopolymer.

The suture 38 is formed into a loop which extends through the openings64 and 66 in the anchor 50. At this time, the suture 38 has a lengthwhich is substantially greater than the length illustrated in FIG. 2.The cylindrical anchor 50, with the suture 38 connected thereto, is thenpositioned in axial alignment with the tubular member which extendsthrough the passage 40. Thus, the anchor 50 is moved to an orientationin which a longitudinal central axis of the anchor is coincident withthe longitudinal central axis of the cylindrical passage in the tubularmember which extends through the passage 40 in the bone 20.

The leading end 58 of the anchor 50 is then moved into the cylindricaltubular member which forms a liner for the passage 40. A pusher memberpushes the anchor 50 from an upper (as viewed in FIG. 2) end of thetubular member along the passage 40 in the bone 20 and through theoutlet 84 from the passage. As the anchor 50 moves through the passage40, the suture 38 is pulled through the passage 40 by the anchor.

The orientation of the anchor 50 is then changed from an orientation inwhich the longitudinal central axis of the anchor 50 is aligned with thelongitudinal central axis of the passage 40 to an orientation in whichthe longitudinal central axis of the anchor 50 extends generallyperpendicular to the longitudinal central axis of the passage 40, i.e.,the orientation shown in FIG. 2. To pivot the anchor 50 to theorientation shown in FIG. 2, as the anchor emerges from the outlet 84,the suture 38 is tensioned. The combination of the tension in the suture38 and force applied against the trailing end 60 of the anchor by thepusher member causes the anchor to pivot about the trailing end 60 ofthe anchor. The pusher member is then withdrawn and the suture tensionedto move the anchor to the position shown in FIG. 2 in a manner similarto that described in the aforementioned U.S. Pat. Nos. 5,527,343 and5,534,012.

Although it is believed that it may be preferred to change theorientation of the anchor 50 after it has emerged from the passage 40,the anchor could be blocked from reentering the passage in other ways ifdesired. Thus, the anchor could expand after emerging from the passage40. This could be accomplished by having spring biased arms held in aretracted position by engagement of spring biased arms with the innerside surface of the tubular cylindrical member which lines the passage40. Upon emerging from the passage, the arms would move outward underthe influence of spring forces and extend radially outward beyond theedge of the exit from the passage 40. If desired, the anchor 50 could beconstructed so as to expand in a manner similar to that disclosed inU.S. Pat. Nos. 5,397,331 and/or 4,409,974.

Rather than expanding under the influence of stored energy, such asspring force, the anchor 50 could expand by absorbing body fluids. Thus,the anchor 50 may be compressed when it moves through the passage 40 andwill expand and absorb body fluids after emerging from the passage 40.It is contemplated that the anchor 50 could be constructed so as toexpand in any one of the ways disclosed in U.S. patent application Ser.No. 08/699,553 filed Aug. 19, 1996 by Peter M. Bonutti and entitled“Suture Anchor”.

The cylindrical tubular member is then withdrawn from the passage 40. Itshould be understood that the cylindrical tubular member is used to linethe passage 40 in the bone 20 during movement of the anchor 50 throughthe passage. The use of the tubular member to line the passage 40 may beomitted if desired. However, if the use of the tubular member to linethe passage 40 is omitted, the anchor 50 and pusher member would beexposed to the cancellous bone tissue 44 during movement of the anchorthrough the passage.

The limbs 72 and 74 of the suture 38 are then threaded through openings64 and 66 in the second suture anchor 52. The limbs 72 and 74 of thesuture 38 are tensioned and the second anchor 52 is pressed against theouter side surface of the bone 20. While a predetermined tension forceis maintained in the limbs 72 and 74 of the suture 38, the knot 78 istied in the suture to interconnect the two suture anchors 50 and 52 withthe suture 38. The suture 38 is then trimmed to the desired length.

Once the knot 78 has been tied between the limbs 72 and 74 of the suture38, the tension in the suture 38 presses the side surfaces 28 and 30 ofthe fracture 26 together. This pressure between the side surfaces 28 and30 of the fracture 26 is maintained by the suture 38 and suture anchors50 and 52 until the fracture heals. It is believed that it may bepreferred to form the suture 38 and suture anchors 50 and 52 of abiodegradable material which, after the fracture 26 has healed, willdissolve in the patient's body.

The cylindrical tubular member which is inserted into the passage 40through the bone 20 performs the dual functions of lining the inside ofthe passage 40 and maintaining the two sections 22 and 24 of the bone inalignment. The cylindrical tubular member could have a slot formed in aside wall of the tubular member to facilitate insertion of the tubularmember into the passage 40. It is contemplated that the cylindricaltubular member could be left in the passage 40 after the bone sutureassembly 32 has been installed. If the slotted or unslotted cylindricaltubular member is to be left in the passage 40, the cylindrical tubularmember may be formed of a biodegradable or bioerodible copolymer. Whenthe cylindrical tubular member remains in the passage 40, the suture 38extends through the tubular member.

Although only a knot 78 has been shown in FIG. 2 adjacent to the secondanchor 52, a suture retainer could be provided to further hold the limbs72 and 74 of the suture 38. If a suture retainer is to be used inassociation with the knot 78, the suture retainer will be moved alongthe limbs of the suture 38 toward the knot before the limbs 72 and 74 ofthe suture are trimmed to the short length shown in FIG. 2. The sutureretainer would then be plastically deformed to grip the limbs 72 and 74of the suture 38. Thereafter, the suture limbs 72 and 74 would betrimmed to a desired length.

BONE SUTURE ASSEMBLY—SECOND EMBODIMENT

In the embodiment of the invention illustrated in FIG. 2, a pair ofsuture anchors 50 and 52 are connected with the suture 38 to maintaintension in the suture and pressure against opposite side surfaces 28 and30 of the fracture 26. In the embodiment of the invention illustrated inFIG. 3, a suture retainer is used in place of one of the suture anchors.Since the embodiment of the invention illustrated in FIG. 3 is generallysimilar to the embodiment of the invention illustrated in FIG. 2,similar numerals will be utilized to designate similar components, thesuffix letter “a” being associated with the embodiment of the inventionillustrated in FIG. 3 to avoid confusion.

A bone 20 a has sections 22 a and 24 a which are separated by a fracture26 a. The fracture 26 a has side surfaces 28 a and 30 a which arepressed together by a bone suture assembly 32 a. A suture 38 a extendsthrough a cylindrical passage 40 a which extends diametrically throughthe generally cylindrical bone 20 a. The suture 38 a has a pair of limbsor sections 72 a and 74 a which are connected with a suture anchor 50 a.The suture anchor 50 a has the same construction as the suture anchor 50of FIG. 2.

In accordance with a feature of this embodiment of the invention, asuture retainer 92 is used in place of the suture anchor 52 of FIG. 2.The suture retainer 92 has a spherical configuration. A cylindricalpassage 94 extends through the center of the spherical suture retainer92. The sections 72 a and 74 a of the suture 38 a extend around thespherical outer side surface of the suture retainer 92. Thus, a loop isformed in each of the sections 72 a and 74 a around portions of thesuture retainer 92.

If desired, the suture retainer 92 could have a different configuration.For example, the suture retainer 92 could have an oval or ellipticalconfiguration. Although the passage 94 has a linear central axis, thepassage could have a nonlinear central axis. If desired, a plurality ofpassages having the same or different configurations could be providedin the suture retainer 92.

After the suture 38 a has been inserted through the suture retainer 92,in the manner illustrated schematically in FIG. 3, the suture retainer92 is moved along the sections 72 a and 74 a of the suture 38 a towardthe bone 20 a. The suture retainer 92 is formed as one piece of apolymeric material having a relatively low coefficient friction.Therefore, the two sections 72 a and 74 a of the suture 30 a can readilyslide along the surfaces of the suture retainer 52 a while the sutureretainer moves toward the bone 20 a.

A predetermined tension is maintained in the sections 72 a and 74 a ofthe suture 38 a while the suture retainer 92 is pressed against the bone20 a. This results in the suture 38 a being pulled tightly against thesuture anchor 50 a. The tension in the suture 38 a is effective to pressthe suture anchor 50 a and retainer 92 against opposite sides of thebone 20 a with a predetermined force.

Once the suture retainer 92 has been moved along the suture 38 a and isbeing pressed against the bone 20 a with a predetermined force, thesuture retainer is plastically deformed to grip the sections 72 a and 74a of the suture 38 a. An apparatus 98 for pressing the suture retainer92 against the bone 20 a includes a tubular cylindrical plunger 102(FIG. 3) having a cylindrical central passage through which the sections72 a and 74 a of the suture 38 a extend. The plunger 102 is enclosed bya tubular cylindrical housing 106. The plunger 102 is pressed downward,relative to the housing 106 with a predetermined force, indicated byarrows 108 and 110 in FIG. 3. An annular transducer or load cell 114provides an output indicative of the magnitude of the force 108 and 110with which the suture retainer 92 is pressed against the bone 20 a bythe plunger 102.

While the sections 72 a and 74 a of the suture 38 a are being tensionedwith a predetermined force and while the plunger 102 is being pressedagainst the suture retainer 92 with a predetermined force, the sutureretainer 92 is plastically deformed. To plastically deform the sutureretainer 92, a plurality of force applying or clamp members 120 and 122are pressed against the suture retainer 92 with a predetermined minimumforce, indicated schematically by arrows 126 in FIG. 3. The forceapplication members 120 and 122 may have an arcuate configuration toconform to the spherical configuration of the suture retainer 92 or mayhave a flat configuration. The force applied against the suture retainer92 by the force applying members 120 and 122 is sufficient to causeplastic deformation of the material of the suture retainer.

The force 126 is applied against the suture retainer 92 while the sutureretainer is at a temperature which is below the transition temperatureof the biodegradable polymer which forms the suture retainer 92. Thus,the suture retainer 92 is at approximately the same temperature as thebone 20 a when the force 126 is applied against the suture retainer. Theforce 126 causes the material of the suture retainer 92 to flow and gripthe sections 72 a and 74 a of the suture 38 a.

Upon disengagement of the force application members 120 and 122 from thesuture retainer 92, the application of downward (as viewed in FIG. 3)force against the suture retainer 92 is interrupted. The upwardtensioning of the sections 72 a and 74 a of the suture 38 a is alsointerrupted. At this time, the plastically deformed suture retainer 92securely grips the two sections 72 a and 74 a of the suture 38 a tomaintain the tension in the suture 38 a. If desired, a knot may beformed between the sections 72 a and 74 a of the suture as additionalprotection against the suture working loose over an extended period oftime.

The suture retainer 92 may be formed of many different materials.However, it is believed that it will be preferred to form the sutureretainer 92 of a biodegradable polymer. One biodegradable polymer whichmay be utilized is polycaperlactone. Alternatively, the suture retainer92 could be formed of polyethylene oxide terephthalate or polybutyleneterephthalate. It is also contemplated that other biodegradable orbioerodible copolymers could be utilized.

Although it is preferred to form the suture retainer 92 of abiodegradable material, the suture retainer could be formed of amaterial which is not biodegradable. For example, the suture retainer 92could be formed of an acetyl resin, such as “DELRIN” (trademark).Alternatively, the suture retainer 92 could be formed ofpara-dimethylamino-benzenediazo sodium sulfonate, such as “DEXON”(trademark). The construction of the suture retainer 92 and the mannerin which is cooperates with the suture 38 a is the same as is disclosedin U.S. patent application Ser. No. 08/905,084 filed Aug. 1, 1997 byPeter M. Bonutti et al. and entitled “Method and Apparatus for Securinga Suture”.

The suture retainer 92 is plastically deformed to grip the limbs 72 aand 74 a of the suture 38 a. However, the suture retainer 92 could beconstructed so as to be mechanically actuated to grip the suture 38 a.If desired, a combination of a mechanical gripping action and plasticdeformation could be utilized by a retainer to grip the suture 38 a.

Retaining Body Tissue Against Bone

In the embodiment of the invention illustrated in FIG. 2, a bone sutureassembly 32 is utilized to press surfaces 28 and 30 of a fracture 26together. In the embodiment of the invention illustrated in FIG. 4, thesuture anchor assembly is utilized to hold body tissue against movementrelative to a bone. Since the embodiment of the invention illustrated inFIG. 4 is generally similar to the embodiments of the inventionillustrated in FIGS. 2 and 3, similar numerals will be utilized inassociation with similar components, the suffix letter “b” beingassociated with the numerals of FIG. 4 to avoid confusion.

A cylindrical passage 40 b extends diametrically through a generallycylindrical bone 20 b. A bone suture assembly 32 b is utilized to retainbody tissue 132 against movement relative to the bone 20 b. The bodytissue 132 may be a muscle, ligament, cartilage or other tissue which isto be held against movement relative to the bone 20 b.

The bone suture assembly 32 b includes a first suture anchor 50 b and asecond suture anchor 52 b. A suture 38 b extends through the passage 40b and interconnects the suture anchors 50 b and 52 b. Tension in thesuture 38 b presses the body tissue 132 against a side surface area onthe bone 20 b. The suture 38 b has sections or limbs 72 b and 74 b whichextends through openings in the suture anchors 50 b and 52 b in themanner previously explained. A knot 78 b interconnects the sections 72 band 74 b of the suture 38 b to press the suture anchor 52 b firmlyagainst the body tissue 132. Although the illustrated suture has a pairof sections 72 b and 74 b, the suture could have a single section ifdesired.

The suture anchor assembly 32 b is installed in association with thebone 20 b and body tissue 132 in the same manner as previously explainedin conjunction with the embodiment of the invention illustrated in FIG.2. Thus, the passage 40 (FIG. 4) is formed in the bone 20 b by drillingor other methods. The body tissue 132 may be offset to one side of thelocation where the passage 40 b is formed during formation of thepassage. This enables the passage 40 b to be formed in the bone 20 bwithout damaging the body tissue 132.

The suture anchor 50 b is moved through the passage 40 b with alongitudinal central axis of the suture anchor aligned with thelongitudinal central axis of the passage 40 b. When the suture anchor 50b emerges from the passage 40 b, the anchor is pivoted to theorientation shown in FIG. 4. Alternatively, the anchor 50 b may bemechanically expanded after emerging from the passage 40 b. Acylindrical tubular member may be used to line the passage 40 a duringmovement of the anchor 50 b through the passage in the manner previouslydescribed in connection with the embodiment of FIG. 2.

After the anchor 50 b has been moved to the position shown in FIG. 4,the body tissue 132 is positioned between the limbs 72 b and 74 b of thesuture 38 b. The limbs 72 b and 74 b of the suture 38 b are theninserted through the openings in the suture anchor 52 b. While apredetermined tension is maintained in the suture 38 b, the knot 78 b istied between the limbs 72 b and 74 b of the suture. This results in thebody tissue 132 being pressed against the bone 20 b with a predeterminedforce. A button or other force distributing member may be providedbetween the suture anchor 52 b and body tissue 132 if desired.

In the embodiment of the invention illustrated in FIG. 4, two sutureanchors 50 b and 52 b are utilized to press the body tissue 132 againstthe bone 20 b. However, a suture retainer could be substituted for oneor more of the suture anchors 50 b or 52 b. For example, a sutureretainer having the same construction and installed in the same manneras the suture retainer 92 of FIG. 3 could be substituted for the anchor52 b of FIG. 4. It should be understood that the suture retainersubstituted for the anchor 52 b of FIG. 4 could have any desiredconstruction. Thus, a suture retainer having the construction of any oneof the suture retainers disclosed in the aforementioned U.S. patentapplication Ser. No. 08/905,084 filed Aug. 1, 1997 by Peter M. Bonuttiet al. and entitled “Method and Apparatus for Securing a Suture” couldbe utilized in place of the anchor 52 b and/or the anchor 50 b.

When a suture retainer is used in place of the anchor 52 b, the sutureretainer applies force against the body tissue 132 to press the bodytissue against the bone 20 b. If desired, a force distribution membercould be provided between the suture retainer and the body tissue 132.

Although the passage 40 b has been illustrated in FIG. 4 as having alinear configuration, the passage could have a nonlinear configurationif desired.

In the embodiment of the invention illustrated in FIG. 4, body tissue132 is disposed adjacent to only one side of the bone 20 b. However, ifdesired, body tissue could be disposed adjacent to opposite sides of thebone 20 b. The body tissue could be connected with the anchor 50 b inmany different ways. For example, a separate length of suture could beconnected with the body tissue and anchor 50 b or with the suture 38 badjacent to the anchor 50 b.

An alternative manner of connecting body tissue with the side of thebone adjacent to the anchor 50 b would be to insert the body tissuebetween the limbs 72 b and 74 b of the suture 36 b in the same manner asshown with the anchor 52 b. If this is to be done, an end portion of thebody tissue may be manually inserted between the limbs 72 b and 74 b ofthe suture 38 b. If a central portion of the body tissue is to bedisposed between the anchor 50 b and the bone 20 b, the connectorsection 76 b of the suture could be cut. One of the limbs 72 b or 74 bof the suture would then be separated from the anchor 50 b. The bodytissue would be inserted between the limbs of the suture 38. Theseparated end of the suture would then be inserted through the anchor 50b and connected with the other limb of the suture 38 b.

In the embodiment of the invention illustrated in FIG. 4, the bodytissue 132 is pressed against a bone 20 b which has not been fractured.However, it is contemplated that the bone suture assembly 32 could beutilized to perform the dual functions of pressing body tissue against abone and of pressing opposite side surfaces of a fracture together. Thiswould result in the body tissue being pressed against the bone 20 b inthe manner illustrated in FIG. 4 and in opposite side surfaces of afracture being pressed together in the manner illustrated in FIG. 2 forthe opposite side surfaces 28 and 30 of the fracture 26.

Nonlinear Suture Passage

In the embodiment of the invention illustrated in FIG. 2, the passage 40through which the suture 38 extends has a linear configuration. In theembodiment of the invention illustrated in FIG. 5, the passage throughwhich the suture extends has a nonlinear configuration. Since theembodiment of the invention illustrated in FIG. 5 is generally similarto the embodiment of the invention illustrated in FIGS. 2-4, similarnumerals will be utilized to identify similar components, the suffixletter “c” being associated with the components of the embodiment of theinvention illustrated in FIG. 5 to avoid confusion.

A bone 20 c as a fracture 26 c which divides the bone into two sections22 c and 24 c. Opposite side surfaces 28 c and 30 c of the fracture 26 care pressed together by a bone suture assembly 32 c. The bone sutureassembly 32 c includes a suture 38 c which extends between first andsecond suture anchors 50 c and 52 c.

In accordance with a feature of this embodiment of the invention, thesuture 38 c is disposed in a passage 40 c having a nonlinearconfiguration. Thus, the passage 40 c includes a first section 140 whichis skewed relative to a second section 142 of the passage 40 c. A bend144 is formed in the passage 40 c at an intersection 146 of the firstand second sections 140 and 142 of the passage 40 c. The flexible suture38 c extends around the bend 144 along a nonlinear path between thesuture anchors 50 c and 52 c. At the bend 144, the suture 38 c appliesforce against the section 24 c of the bone 20 c urging the section 24 ctoward the left (as viewed in FIG. 5). This force presses the sections22 c and 24 c of the bone 20 c firmly together at the fracture 26 c.

The suture anchors 50 c and 52 c have the same cylindrical constructionas the suture anchors 50 and 52 in the embodiment of the inventionillustrated in FIG. 2. A knot 78 c (FIG. 5) is provided between limbs ofthe suture 38 c to maintain a desired tension in the suture 38 c. Thistension pulls the suture anchors 50 c and 52 c toward each other. Inaddition, this tension presses the section 24 c of the bone 20 c firmlyagainst the section 22 c of the bone at the fracture 26 c.

The first section 140 of the passage 40 c is formed at an angle to andextends through a longitudinal central axis of the generally cylindricalbone 20 c. The second section 142 of the passage 40 c is formed in adirection perpendicular, i.e., along a radius, of the generallycylindrical bone 20 c. The two sections 140 and 142 of the passage 40 cterminate in the spongy cancellous bone tissue 44 c.

When the suture assembly 32 c is to be used to treat the fracture 26 cin the bone 20 c, the two sections 22 c and 24 c of the bone are pressedtogether at the fracture 26 c to align the side surfaces 28 c and 30 cof the fracture. A drill or other hole forming apparatus is then used toform the first section 140 of the passage 40 c. The drill or other holeforming apparatus is then used to form the second section 142 of thepassage 40 c. When the second section 142 of the passage 40 c intersectsthe first section 140 of the passage 40 c, formation of the section 142of the passage 40 c is interrupted.

Once the nonlinear passage 40 c has been formed in the two sections 22 cand 24 c of the bone 20 c, a tubular cylindrical liner (not shown) isinserted into the passage 40 c. The tubular cylindrical liner may beformed by two separate tubular members which are inserted at oppositeends of the passage 40 c. Alternatively, the tubular cylindrical linermay be formed by a single flexible tubular member which is inserted intothe section 140 of the passage 40 c and then moved around the bend 144into the section 142 of the passage 40 c. It should be understood thatthe tubular cylindrical liner for the passage 40 c could be omitted ifdesired.

The cylindrical anchor 50 c, with the suture 38 c connected thereto, isthen positioned in axial alignment with the section 142 of the passage40 c. The leading end 58 c of the anchor 50 c is then moved into thelined section 142 of the passage 40 c. A flexible pusher member appliesforce against the trailing end 60 c of the anchor 50 c and pushes theanchor around the bend 144 and through the section 140 of the passage 40c.

Alternatively, a flexible wire or other member could be inserted intothe section 140 of the passage 40 c. The wire would move around the bend144 and extend outward from the section 142 of the passage. The wirewould then be connected with the anchor 50 c and suture 38 c. Theleading end 58 c of the anchor 50 c would then be inserted into thesection 142 of the passage 40 c. Tension on the wire would pull theanchor 50 c around the bend 144 and out of the section 140 of thepassage 40 c.

Once the anchor 50 c has been moved out of the passage 40 c, the tubularliner for the passage may be withdrawn. If a one-piece tubular liner isused, it may be withdrawn from the open end of the section 142 of thepassage 40 c. If a two-piece liner is used, one of the pieces may bewithdrawn from the open end of the passage section 140 and slit to clearthe suture 38 c. Alternatively, the slit could be formed in the piece ofthe liner before it is inserted into the passage section 140. The otherpiece of the liner would be withdrawn from the open end of the passagesection 142. Alternatively, the tubular liner for the passage 40 c maybe left in place. Of course, the use of a tubular liner for the passage40 c may be omitted.

The suture 38 c is then threaded through openings in the suture anchor52 c. The suture 38 c is then tensioned and the second anchor 52 c ispressed against the outer side surface of the bone 20 c. While apredetermined tension force is maintained in the suture 38 c, the knot78 c is tied.

In the illustrated embodiment of the invention, the two sections 140 and142 of the passage 40 c have a straight cylindrical configuration.However, it is contemplated that the sections 140 and 142 of the passage40 c could have a different configuration if desired. For example, thesection 140 and/or 142 of the passage 40 c could have a nonlinearcentral axis and could have a noncircular cross-sectional configurationof desired.

Body tissue, corresponding to the body tissue 132 of FIG. 4 could bedisposed between the anchor 50 c and/or 52 c and the bone 20 c. Althoughthe suture 38 c has been illustrated as having a pair of limbs orsections which extend between the anchors 50 c and 52 c, the suture 38 ccould have a single limb or section if desired. The anchor 50 c couldmechanically expand, by absorbing body liquid or under the influence ofexpansion springs, after the anchor has emerged from the passage 40 c toprevent the anchor from being pulled back through the passage.

Nonlinear Passage—Second Embodiment

In the embodiment of the invention illustrated in FIG. 5, the bonesuture assembly 32 c associated with the nonlinear passage 40 c includesa pair of suture anchors 50 c and 52 c. In the embodiment of theinvention illustrated in FIG. 6, a suture retainer in substituted forone of the suture anchors in much the same manner as previouslydescribed in conjunction with the embodiment of the inventionillustrated in FIG. 3. Since the embodiment of the invention illustratedin FIG. 6 is generally similar to the embodiment of the inventionillustrated in FIGS. 2-5, similar numerals will be utilized to designatesimilar components, the suffix letter “d” being associated with thenumerals of FIG. 6 in order to avoid confusion.

A bone 20 d has a fracture 26 d which divides the bone into two sections22 d and 24 d. The fracture 26 d has side surfaces 28 d and 30 d whichare pressed together by a bone suture assembly 32 d. The bone sutureassembly 32 d includes a suture 38 d which extends through a nonlinearpassage 40 d having the same construction as the nonlinear passage 40 cof FIG. 5.

In accordance with a feature of this embodiment of the invention, thebone suture assembly 32 d includes a suture anchor 50 d having the sameconstruction as the suture anchor 50 of FIG. 2, and a suture retainer 92d having the same construction as the suture retainer 92 of FIG. 3. Thesuture anchor 50 d and suture retainer 92 d maintain a predeterminedtension in the suture 38 d. This results in the suture anchor 50 d beingfirmly pressed against the section 24 d of the bone 20 d. The sutureretainer 92 d is firmly pressed against the section 22 d of the bone 20d by the tension in the suture 38 d.

Since the passage 40 d has a nonlinear configuration, the suture 38 d iseffective to apply a force component to the section 24 d of the bone 20d urging the section 24 d of the bone toward the left (as viewed in FIG.6). This results in the surface 30 d of the fracture 26 d being pressedfirmly against the surface 28 d of the fracture.

The suture retainer 92 d is plastically deformed to grip the suture 38 din the same manner as previously described herein in conjunction withthe suture retainer 92 of FIG. 3. However, the suture retainer 92 dcould be constructed so as to form a mechanical connection with thesuture 38 d. If desired, a suture retainer could be substituted for theanchor 50 d.

Although both the suture retainer 92 d and anchor 50 d have beenillustrated in FIG. 6 as being disposed in engagement with the bone 20d, a force distributing member could be provided between the anchorand/or suture retainer and the bone. It is contemplated that bodytissue, similar to the body tissue 132 of FIG. 4, could be disposedbetween the anchor 50 d and/or the suture retainer 92 d and the bone 20d.

Tissue Tensioning with Bone Fragment Retaining

In the embodiment of the invention illustrated in FIG. 2, the fracturein a portion of a bone is treated. In the embodiment of the inventionillustrated in FIGS. 7 and 8, a fracture results in a fragment of a bonebeing separated from a main portion of the bone. The bone fragment isconnected with the main portion of the bone by muscle, tendon, ligament,cartilage or other fibrous body tissue. In the embodiment of theinvention illustrated in FIGS. 7 and 8, the fibrous body tissue istensioned as the bone fragment is positioned relative to the mainportion of the bone. Since the embodiment of the invention illustratedin FIGS. 7 and 8 is generally similar to the embodiment of the inventionillustrated in FIGS. 2-6, similar numerals will be utilized to designatesimilar components, the suffix “e” being associated with the numerals ofFIGS. 7 and 8 in order to avoid confusion.

A bone fragment 154 is separate from a main bone 20 e (FIG. 7). Thefragment 154 is connected with the main bone 20 e by fibrous body tissue158, i.e., muscle, tendon, ligament, cartilage, etc. The fibrous bodytissue 158 extends between the bone fragment 154 and a portion 160 ofthe main bone 20 e. The bone fragment 154 has a side surface 28 e with aconfiguration which matches the configuration of a side surface 30 e ofa fracture 26 e which occurred in the main bone 20 e.

In order to promote healing of the main bone 20 e, a bone sutureassembly 32 e (FIG. 8) is utilized to pull the bone fragment 154 towardthe main bone 20 e. As this occurs, the fibrous body tissue 158 istensioned and the side surface 28 e on the bone fragment 154 is pressedagainst the side surface 30 e on the main bone 20 e. The bone fragment154 is pressed firmly against the main bone 20 e by the bone sutureassembly 32 e. Thus, the gap illustrated schematically in FIG. 8,between the side surfaces 28 e and 30 e of the fracture 26 e, iseliminated and the side surfaces of the fracture are pressed firmlytogether by the bone suture assembly 32 e. If desired, the bone fragment154 may be manually pressed against the main bone 20 e before the bonesuture assembly is pulled tight.

The bone suture assembly 32 e includes a suture 38 e having limbs orsections 72 e and 74 e. The suture 38 e extends through openings in afirst suture anchor 50 e. The suture then extends into a passage 40 eformed in the bone fragment 154 and the main bone 20 e.

The passage 40 e includes a first section 140 e which extends throughthe bone fragment 154. In addition, the passage 40 e includes a secondsection 142 e which extend through the main bone 20 e. The limbs orsection 72 e and 74 e of the suture 38 e extends through a second anchor52 e.

During installation of the bone suture assembly 32 e, the limbs 72 e and74 e of the suture 38 e are gripped by a force or tension measurementdevice 98 e. The tension measurement device 98 e includes a load cellwhich measures the amount of tension applied to the limbs 72 e and 74 eof the suture 38 e.

As tension is applied to the limbs 72 e and 74 e of the suture 38 e, thebone fragment 154 is pulled toward the right (as viewed in FIG. 8) tomove the side surface 28 e on the bone fragment into alignment with theside surface 30 e on the main bone 20 e. As this occurs, the fibrousbody tissue 158 is stretched or tensioned. While a predetermined forceis transmitted through the limbs 72 e and 74 e to the suture anchor 50 eand the bone fragment 154 to firmly press the bone fragment against themain bone 20 e, a knot 78 e is tied to interconnect the limbs 72 e and74 e. While the predetermined tension is maintained and the knot 78 etied, the second anchor 52 e is firmly pressed against the side surfaceof the main bone 20 e.

Although the passage 40 e could have a linear configuration if desired,in the embodiment of the invention illustrated in FIG. 8, the passage 40e has a nonlinear configuration. Thus, the first section 140 e of thepassage 40 e has a central axis which is skewed relative to a centralaxis of the second section 142 e of the passage 40 e. This enables theflexible suture 38 e to apply force to the bone fragment 154 havingcomponents urging the bone fragment rightward (as viewed in FIG. 8)against the surface 30 e on the main bone 20 e and downward (as viewedin FIG. 8) to maintain the tension in the fibrous body tissue 158.

When the passage 40 e is to be formed in the bone fragment 154 and mainbone section 20 e, a hole is drilled through the bone fragment 154 toform the first section 140 e of the passage. The second portion 142 e ofthe passage 40 e is drilled in the main bone 20 e. It should beunderstood that the passage 40 e could be formed in many different waysother than drilling. For example, a cutting tool or laser could be usedto form the passage 40 e.

The second section 142 e of the passage 40 e has a longitudinal centralaxis which is skewed at an acute angle relative to the longitudinalcentral axis of the first section 140 e of the passage in the bonefragment 154. Thus, the first portion 140 e of the passage 40 e in thebone fragment 154 has a central axis which is close to beingperpendicular to a longitudinal central axis of the main bone 20 e. Thesecond portion 142 e of the passage 40 e has a longitudinal central axiswhich is angularly offset to a substantial arc relative to thelongitudinal central axis of the main bone 20 e.

The anchor 50 e is moved through the first section 140 e of the passage40 e and positioned in engagement with an outer side surface of the bonefragment. The free ends of the limbs 72 e and 74 e of the suture 38 eare then moved rightward (as viewed in FIG. 8) through the secondportion 142 e of the passage 40 e. The free ends of the suture 38 e arethen threaded through openings in the second anchor 52 e.

After the suture 38 e has been inserted through openings in the secondanchor 52 e, the force or tension measuring device 98 e is utilized topull the free ends of the suture 38 e toward the right (as viewed inFIG. 8). This tension pulls the bone fragment 154 into engagement withthe main bone 20 e. The knot 78 e is tied in the free ends of the suture38 e while the tension is maintained in the suture.

If desired, the bone suture assembly 32 e could be positioned relativeto the bone 20 e and the bone fragment 154 by moving the anchor 50 efirst through the second section 142 e of the passage disposed in themain bone 20 e and then through the first section 140 e of the passagedisposed in the fragment 154. The free ends of the suture would then beinserted through the second anchor 52 e. The suture 38 e would betensioned to pull the bone fragment 154 into place with the side surface28 e in aligned engagement with the surface 30 e on the main bone 20 e.The knot 78 e would then be tied while maintaining the desired tensionin the suture 38 e.

It should be understood that the anchor 52 e and knot 78 e could bepositioned adjacent to the bone fragment 154 and the anchor 50 epositioned adjacent to the bone 20 e. Although only a single bone sutureassembly 32 e has been illustrated in FIG. 8, multiple bone sutureassemblies could be used to position the bone fragment 154 relative tothe bone 20 e.

In the embodiment of the invention illustrated in FIGS. 7 and 8, thebone suture assembly 32 e includes a pair of anchors 50 e and 52 e. Ifdesired, a suture retainer could be substituted for either or both ofthe anchors 50 e and 52 e. Thus, a suture retainer having a constructionsimilar to the construction of the suture retainer 92 of FIG. 3 could beused in place of the second anchor 52 e. It should be understood thatthe suture retainer 92 could have the same construction as any one ofthe suture retainers disclosed in the aforementioned U.S. patentapplication Ser. No. 08/905,084 filed Aug. 1, 1997 by Peter M. Bonuttiet al. and entitled “Method and Apparatus for Securing a Suture”.

In the embodiment of the invention illustrated in FIG. 8, the anchors 50e and 52 e are placed in engagement with the bone of fragment 154 andmain bone 20 e. However, it is contemplated that the anchor 50 e and/or52 e could be positioned in engagement with body tissue other than bone.For example, the anchor 50 e could be positioned in engagement with aportion of the fibrous body tissue 158 to position the fibrous bodytissue 158 relative to the bone fragment 154 and to more securelyinterconnect the fibrous body tissue and the bone fragment. If desired,body tissue could be positioned between the anchor 52 e and the mainbone 20 e.

In FIG. 8, there is a single bone fragment 154. However, fractures mayoccur in such a manner as to have a plurality of bone fragments. Aplurality of bone suture assemblies 32 e could be utilized tointerconnect the plurality of bone fragments and the main bone.

When a fracture occurs in such a manner as to form a plurality of bonefragments, it may be desired to use bone suture assemblies 32 e inassociation with only the larger bone fragments. If desired, a bridge orcover member could extend across the bone fragments to position the bonefragments relative to each other. One or more bone suture assemblies 32e would extend through one or more of the larger bone fragments andthrough the bridge or cover member. Force applied against the bridge orcover member by an anchor or anchors in a bone suture assembly orassemblies 32 e would urge the bridge or cover member toward the mainbone 20 e to position the smaller bone fragments relative to the largerbone fragments and main bone 20 e and to press the bone fragmentsagainst each other and against the main bone.

One or more of the anchors 50 e and 52 e could be formed of body tissueor of material which absorbs body fluid and expands. Alternatively, oneor more of the anchors 50 e or 52 e could be mechanically expanded toblock movement into the passage 50 e.

Bone Fragment Retention

In the embodiment of the invention illustrated in FIG. 2, the bonesuture assembly 32 extends between diametrically opposite outer sidesurface areas on the bone 20. This results in the first suture anchor 50being disposed against an outer side surface of the hard outer layer 42of the bone 20 (FIG. 1) and the suture anchor 52 being disposed againstthe outer side surface of the hard outer layer 42 on the opposite sideof the bone. In the embodiment of the invention illustrated in FIG. 9,one of the anchors is disposed within the bone and the other anchor isdisposed outside of the bone. Since the embodiment of the inventionillustrated in FIG. 9 is generally similar to the embodiment of theinvention illustrated in FIGS. 2-8, similar numerals will be utilized toidentify similar components, the suffix letter “f” being associated withthe numerals of FIG. 9 in order to avoid confusion.

A bone 20 f has a hard outer layer 42 f which encloses spongy cancellousbone tissue 44 f. A fragment 164 has broken away from the hard outerlayer 42 f. A bone suture assembly 32 f is used to position and hold thefragment 164 in engagement with the bone 20 f. The bone suture assembly32 f includes a first suture anchor 50 f which is disposed in engagementwith an inner side surface 166 of the outer layer 42 f of bone. A secondanchor 50 f is disposed in engagement with an outer side surface 168 ofthe fragment 164. A suture 38 f extends between the first and secondanchors 50 and 52 f. The suture 38 f extends through a passage 40 fwhich extends across a fracture 26 f.

When the bone suture assembly 32 f is used to position the fragment 164against the outer layer 42 f of the bone 20 f, the fragment 164 isaligned with the outer layer 42 f of the bone 20 f. At this time, a sidesurface 172 on the fragment 164 is disposed in aligned engagement with aside surface 174 on the bone 20 f. The two side surfaces 172 and 174were formed by breaking away of the fragment 164 from the outer layer 42f of the bone.

Once the fragment 164 has been aligned with the bone 20 f, the linearpassage 40 f is formed by drilling or other methods through the fragment164 and the outer layer 42 f of bone. A cylindrical tubular member (notshown) having a thin cylindrical side wall is then inserted through thepassage 40 f. The first anchor 50 f is moved to an orientation in whicha longitudinal central axis of the first anchor is aligned with alongitudinal central axis of the cylindrical tubular member.

The first anchor 50 f is then moved through the cylindrical tubularmember, across the fracture 26 f and into the spongy cancellous bonetissue 44. A pusher member applies force against a trailing end of afirst anchor 50 f to push the anchor through the tubular member. Whenthe leading end of the first anchor 50 f emerges from the passage 40 f,the longitudinal central axis of the first anchor is aligned with thelongitudinal central axis of the passage 40 f.

The first anchor 50 f is then pivoted through 90 degrees to change itsorientation to the orientation shown in FIG. 9. The tubular member isthen withdrawn from the passage 40 f. The free ends of the suture 38 fare then inserted through openings in the anchor 52 f. The suture istensioned to press the anchor 50 f against the inner side surface 166 onthe outer layer 42 f of the bone 20 f. The second anchor 52 f is pressedagainst the outer side surface 168 or the fragment 164 with apredetermined force by the tension in the suture 38 f. A knot 78 f isthen tied in the free ends of the suture 38 f to maintain the desiredtension in the suture.

Although it is believed that it may be desired to remove the tubularmember from the passage 40 f, the tubular member could be left in thepassage if desired. If the tubular member is to be left in the passage40 f, the tubular member may be formed of a biodegradable or bioerodiblecopolymer. Of course, the use of the tubular member could be eliminatedif desired.

It should be understood that a suture retainer, having a constructionsimilar to the construction of the suture retainer 92 of FIG. 3, couldbe used in place of the second anchor 52 f if desired. Although thesuture anchor 52 f has been shown in FIG. 9 as being disposed in directabutting engagement with the outer side surface 168 of the bone fragment164, a layer of body tissue could be provided between the suture anchor52 f and the outer side surface 168 of the bone fragment 164 to hold thebody tissue against movement relative to the bone 20 f. If desired, aplurality of bone suture assemblies 32 f could be utilized to hold thebone fragment 164.

Use of Plates with Bone Suture Assembly

In the embodiment of the invention illustrated in FIG. 2, the sutureanchors 50 and 52 are disposed in abutting engagement with an outer sidesurface of a bone. In the embodiment of the invention illustrated inFIG. 10, a pair of bone plates and rigid fasteners are used inassociation with a bone suture assembly. Since the embodiment of theinvention illustrated in FIG. 10 is generally similar to the embodimentof the invention illustrated in FIGS. 2-9, similar numerals will beutilized to designated similar components, the suffix “g” beingassociated with the numerals of FIG. 10 to avoid confusion.

A bone 20 g has sections 22 g and 24 g which are separated by a fracture26 g. In accordance with a feature of this embodiment of the invention,a pair of plate members 184 and 186 are used in association with a bonesuture assembly 32 g. The plate members 184 and 186 may be formed of anydesired biocompatible material. Thus, the plate members may be formed ofmetal or a polymeric material. If the plate members 184 and 186 areformed of polymeric material, biodegradable or bioerodible copolymerscould be utilized.

In the illustrated embodiment of the invention, the plate members 184and 186 are rigid and are shaped to engage the bone 20 g. If desired,the plate members 184 and 186 could have sufficient flexibility toenable the plate members to be plastically deformed to the configurationof the bone 20 g after having been positioned in engagement with thebone.

A first suture anchor 50 g is pressed against the plate member 184 bytension in a suture 38 g. The suture 38 g extends through a passage 40 gin the bone 20 g. A second anchor 52 g is pressed against the platemember 186 by the tension in the suture 38 g. A knot 78 g is provided inthe suture 38 g.

A pair of screws 190 and 192 extend diametrically through the bone 20 gbetween the plate members 184 and 186. The screws 190 and 192 areengaged by nuts 196 and 198 which engage the plate member 184. Thescrews 190 and 192 and nuts 196 and 198 cooperate to press the platemembers 184 and 186 against the bone 20 g. If desired, bone sutureassemblies having the same construction as the bone suture assembly 32 gcould be substituted for the screws 190 and 192 and nuts 196 and 198 sothat the plates 184 and 186 would be held in position against the bone20 g by only the plurality of bone suture assemblies 32 g.

The screws 190 and 192 and nuts 196 and 198 may be formed of any desiredbiocompatible material. Thus, the screws 190 and 192 and nuts 196 and198 may be formed of metal or a polymeric material. If the screws 190and 192 and nuts 196 and 198 are formed of polymeric material,biodegradable or bioerodible copolymers could be utilized.

In the illustrated embodiment of the invention, the screws 190 and 192extend through the bone 20 g. It is contemplated that shorter screwscould be utilized if desired. These shorter screws would have relativelycoarse bone engaging thread convolutions to hold the short screws andplate members 184 and 186 in place. The shorter screws would have alength which is less than diameter of the bone 20 g.

In the illustrated embodiment of the invention, the bone suture assembly32 g extends through a linear passage 40 g. If desired, the passage 40 gcould have a nonlinear configuration. If bone suture assemblies 32 g aresubstituted for the screws 190 and 192 and nuts 196 and 198, some of thebone suture assemblies could extend through linear passages while otherbone suture assemblies extend through nonlinear passages.

Installation Method

In the embodiment of the invention illustrated in FIG. 2, the passage 40is formed in the bone 20 by any desired method. A thin walledcylindrical tubular member is then inserted into the passage and thefirst suture anchor 50 moved through the thin walled member. In theembodiment of the invention illustrated in FIGS. 11 and 12, a cannulateddrill is used to drill a passage through a bone and to guide movement ofthe first anchor through the bone. Since the embodiment of the inventionillustrated in FIGS. 11 and 12 is generally similar to the embodimentsof the invention illustrated in FIGS. 2-10, similar numerals will beutilized to identify similar components, the suffix “h” being associatedwith the numerals in FIGS. 11 and 12 to avoid confusion.

A bone 20 h has a fracture (not shown). When the fracture is to betreated with a bone suture assembly 32 h (FIG. 12), a thin elongatedcylindrical member or K-wire 204 is first inserted through the bone 20h. This may be done by rotating the thin elongated member 204 with adrill drive mechanism in the manner indicated by an arrow 206 in FIG.11. The drill drive mechanism is provided with a passage which extendsthrough a drive shaft for the mechanism. While the thin elongated member204 is being rotated by the drill drive mechanism, the K-wire extendsthrough the passage in the drill drive mechanism.

As the thin elongated member 204 is rotated by the drill drivemechanism, it is pressed against the bone 20 h. As the thin elongatedmember 204 is rotated, in the manner indicated by the arrow 206 in FIG.11, the thin elongated member is moved diametrically through thegenerally cylindrical bone 20 h until the leading end of the thinelongated member 204 extends from the opposite side of the bone. Thus,the thin elongated member 204 is moved through the hard outer layer 42 h(FIG. 12) at one side of the bone 20 h, through the spongy or cancellousbone tissue 44 h, and through the hard outer layer at the diametricallyopposite side of the bone. When this has been done, the thin elongatedmember 204 will extend across the fracture in the bone.

The drill drive mechanism is then disengaged from the thin elongatedmember 204. A cannulated drill 210 is moved axially along the thinelongated member until the leading end portion 212 of the drill 210engages the bone 20 h (FIG. 11). The drill 210 is then gripped by thedrill drive mechanism.

While the thin elongated member 204 remains stationary, the drill 210 isrotated about the thin elongated member in the manner indicated by anarrow 214 in FIG. 11. As the drill 210 is rotated about the stationarythin elongated member 204, the drill is moved axially into the bone 20h. As this occurs, the leading end 212 of the drill enlarges the hole orpassage formed in the bone 20 h by the thin elongated member 204. Thedrill 210 is moved along the thin elongated member 204 until the drillextends diametrically across the bone 20 h. This movement of the drill210 is guided by engagement of the thin elongated member 204 with a sidewall of a cylindrical passage 218 which extends axially through thedrill 210. Movement of the drill 210 through the bone 20 h forms apassage 40 h which extends through a fracture in the bone.

Once the drill 210 has been moved diametrically through the generallycylindrical bone 20 h (FIG. 12), the thin elongated member 204 iswithdrawn from the drill. This leaves an open cylindrical passage 218extending through the drill 210 and across the bone 20 h. The passage218 has a diameter which is just slightly greater than the diameter of acylindrical first anchor 50 h of the bone suture assembly 32 h. Thecylindrical first anchor 50 h is axially aligned with the passage 218 inthe drill 210, in the manner shown in FIG. 12. At this time, the suture38 h has been inserted through openings in the first anchor 50 h andsuture limbs or sections 72 h and 74 h extend away from the first anchor50 h, in the manner indicated schematically in FIG. 12.

A cylindrical pusher member 222 is axially aligned with the first anchor50 h and the passage 218 through the drill 210. The pusher member 222 isutilized to push the first anchor 50 h through the drill 210 to the farside of the bone 20 h.

As the first suture anchor 50 h emerges from the passage 28 in the drill210, the anchor is pivoted through ninety degrees. This pivotal movementchanges the orientation of the anchor 50 h from an orientation in whichthe longitudinal central axis of the anchor 50 h is aligned with thelongitudinal central axis of the passage 218 and drill 210 to anorientation in which a longitudinal central axis of the cylindricalanchor 50 h extends perpendicular to the longitudinal central axis ofthe passage and drill. The manner in which the anchor 50 h is pivoted isthe same as is described in the aforementioned U.S. Pat. Nos. 5,527,343and 5,534,012.

The pusher member 222 is then withdrawn from the drill 10 and the drillis withdrawn from the passage formed through the bone 20 h. As thisoccurs, the suture 38 h is tensioned to hold the anchor 50 h in placeagainst the bone 20 h. The drill 210 is then disengaged from the suture38 h. The free limbs 72 and 74 of the suture 38 h are then insertedthrough a second anchor corresponding to the anchor 52 in FIG. 2. Whilea predetermined tension is maintained in the suture 38 h, the suture istied to hold the second suture anchor, corresponding to the sutureanchor 52 in FIG. 2, against the bone 20 h on a side of the boneopposite from the anchor 50 h.

In the foregoing description, the drill 210 has been a rigid drill whichhas been used to form a linear passage to the bone 20 h. However, it iscontemplated that a flexible drill could be utilized to drill a passagethrough the bone. If this was done, the drill could be guided in such amanner as to form a nonlinear passage in the bone.

The foregoing description of how the passage 40 h is formed has been inconjunction with a bone 20 h having a fracture similar to the fracture26 of FIG. 2. However, it is contemplated that the thin elongated member204 and drill 210 could be used to form a passage in a bone which hasnot been fractured (FIG. 4). The thin elongated member 204 and 210 couldbe used to form a passage which extends only part way through a bone(FIG. 9).

In the description of the embodiments of the invention illustrated inFIGS. 1-12, the suture 38 (FIG. 2) has a pair of limbs or sections 72and 74. It is contemplated that the suture 38 could have only a singlelimb which would be connected at one end with the first anchor 50 and atthe opposite end with the second anchor 52. This single limb couldeither be tied off at the second anchor 52 or gripped by a sutureretainer, similar to the suture retainer 92 of FIG. 3.

In the embodiments of the invention illustrated in FIGS. 1-12, thesuture 38 has been formed separately from the first suture anchor 50. Itis contemplated that the first suture anchor 50 could be formed as onepiece with the suture 38. For example, the suture and anchor could beformed as one piece in a manner similar to that disclosed in U.S. Pat.Nos. 4,669,473 or in 4,741,330.

The anchors 50 and 52 in the embodiment of FIGS. 2-12 could have any oneof many different constructions. For example, the anchors could expandby absorbing body fluid. The anchor 50, which is moved through a passage40 in the embodiments of FIGS. 2-12, could mechanically expand uponexiting from the passage.

Positioning of Tubular Member

In the embodiment of the invention illustrated in FIG. 13, a tubularmember is positioned in the passage which extends through the bone.Since the embodiment of the invention illustrated in FIG. 13 isgenerally similar to the embodiments of the invention illustrated inFIGS. 1-12, similar numerals will be utilized to designate similarcomponents, the suffix letter “j” being associated with the numerals ofFIG. 13 to avoid confusion.

A bone 20 j which has been fractured is illustrated in FIG. 1. The bone20 j is divided into two sections 22 j and 24 j by a fracture 26 j.Opposite side surfaces 28 j and 30 j of the fracture 26 j are pressedtogether by bone securing assemblies 32 j.

It should be understood that the bone securing assemblies 32 j may beutilized in the treatment of any one of many different types offractures. The fractures may or may not result in the formation of oneor more bone fragments. In FIG. 13, the bone securing assembly 32 j hasbeen illustrated as interconnecting sections 22 j and 24 j of a completebone fracture of the spiral type. However, the bone securing assemblies32 j could be utilized to connect a fragment of a bone to the mainportion of the bone from which the fragment was broken off.

The bone securing assembly 32 j (FIG. 13) includes a force transmittingmember 38 j which extends across the fracture 26 j. The forcetransmitting member 38 j may be any one of many different types of forcetransmitting members. The force transmitting member 38 j may be formedof human or animal body tissue. However, it is presently preferred touse a suture as the force transmitting member 38 j. Therefore, the forcetransmitting member 38 j will be referred to herein as a suture.

The suture 38 j, that is, the force transmitting member, is disposed ina straight cylindrical passage 40 j which extends diametrically across agenerally cylindrical portion of the bone 20 j. The passage 40 j extendsthrough hard compact tissue of an outer layer 42 j of the bone andthrough spongy or cancellous bone tissue 44 j which is enclosed by thehard outer layer. Although the passage 40 j has a linear configuration,the passage could have a nonlinear configuration if desired.

The suture 38 j extends between a first suture anchor 50 j disposed onone side of the fracture 26 j and a second suture anchor 52 j disposedon the opposite side of the fracture. Tension is maintained in thesuture 38 j to press the suture anchors 50 j and 52 j against oppositesides of the bone 201 with a predetermined force. This force presses theside surfaces 28 j and 30 j of the fracture 26 j firmly together topromote healing of the fracture. If desired, buttons or other forcedistributing members could be provided between the anchors 50 j and 52 jand the bone 20 j. Body tissue could be disposed between the anchors 50j and 52 j and the bone 20 j.

The suture 38 j and/or suture anchors 50 j and 52 j may be formed of anydesired natural or artificial material. For example, the suture 38 j maybe formed of either a polymeric material or a metal. The suture 38 j maybe biodegradable. Any known suture material may be utilized to form thesuture 38 j.

The suture anchors 50 j and 52 j have the same construction. However,the anchor 50 j could have a construction which is different than theconstruction of the anchor 52 j. The anchor 50 j has a cylindrical outerside surface 56 j which extends between smooth rounded end portions 581and 60 j. A pair of parallel cylindrical openings 64 j and 66 j extenddiametrically through the anchor 50 j. The anchor 50 j is free of sharpcorners or projections to avoid cutting or abrading of body tissuedisposed adjacent to the anchor.

The suture anchor 50 j is made of a biocompatible material. Suitablematerials include stainless steel or titanium, cobalt chrome and otherbiocompatible metals. Polymeric material may also be used, suitablepolymeric materials includes polyethylene, polypropylene, andbiodegradable material such as PLA and PGA. It is believed that it maybe preferred to form the suture anchors 50 j and 52 j from biodegradableor bioerodible copolymers. If desired, the anchor 50 j could be formedof body material or hydrophilic materials.

It is contemplated that the anchor 50 j may have any desiredconfiguration. For example, the anchor 50 j could have any one of theconfigurations disclosed in U.S. Pat. No. 5,522,846 issued Jun. 4, 1996and entitled “Suture Anchor”. Alternatively, the suture anchor 50 jcould have the configuration disclosed in U.S. Pat. No. 5,534,012 issuedJul. 9, 1996 and entitled “Method and Apparatus for Anchoring a Suture”.

The cross-sectional size of the anchor 50 j may be such as to enable theanchor to be moved through the passage 40 j. However, the anchor 50 jcould have a size and configuration which would prevent movement of theanchor 50 j through the passage 40 j. For example, the anchors 50 j and52 j could have the same construction as the retainer 92 of FIG. 3.

The length of the anchor 50 j is such as to enable it to span an openingat an end of the passage 40 j and transmit force from the suture 38 j toa substantial area on the outer layer 42 j of the bone 20 j. The lengthof the anchor 50 j may be approximately three times the diameter of theanchor. It is believed that it will be preferred to form the anchor 50 jin such a manner as to eliminate any sharp corners or projections.

In the illustrated embodiment of the invention, the anchor 50 j has acylindrical configuration. This particular anchor has an axial length ofabout two millimeters and a diameter of about one millimeter. Theopenings 64 j and 66 j have a diameter of about one-half millimeter.

It should be understood that the foregoing dimensions have been setforth herein for purposes of clarity of description and it iscontemplated that the size of the anchor 50 j may vary as a function ofthe size of the bone being treated. Thus, relatively small anchors maybe used in association with treatment of small bones in a wrist, hand,foot or ankle of a patient. Relatively large anchors may be used inassociation with treatment of larger bones in an arm, shoulder, leg orhip of a patient. It should be understood that the bone securingassembly 32 j may be used in conjunction with many different bones otherthan the specific bones previously mentioned.

Only a single anchor 50 j or 52 j has been shown at opposite ends of thepassage 40 j. It is contemplated that a plurality of anchors could beprovided at each end of the passage 40 j. For example, a pair ofseparate or interconnected anchors could be provided in a manner similarto that disclosed in the aforementioned U.S. Pat. No. 5,534,012.

In the embodiment of the invention illustrated in FIG. 13, the suture 38j has a pair of limbs or sections 72 j and 74 j which extend through theopenings 64 j and 66 j in the suture anchors 50 j and 52 j. A connectorsection 76 j interconnects the two limbs 72 j and 74 j of the suture 38j and engages a portion of the anchor 50 j. A knot 78 j is formed in theopposite ends of the limbs 72 j and 74 j to interconnect the two limbsof the suture 38 j.

When the knot 78 j is formed, a predetermined tension is present in thelimbs 72 j and 74 j of the suture 38 j. This results in the sutureanchors 50 j and 52 j being pressed firmly against the bone 20 j with apredetermined force. This predetermined force is maintained during andafter tying of the knot 78 j.

When the bone securing assembly 32 j is to be used to treat the fracture26 j in the bone 20 j, the two sections 22 j and 24 j of the bone arepressed together at the fracture 26 j to align the side surfaces 28 jand 30 j of the fracture. A drill is then used to form the passage 40 jwhich extends diametrically through the generally cylindrical bone 20 j.Of course, the passage 40 j could be formed by the use of a tool otherthan a drill. If desired, the passage 40 j could have a noncircularcross-sectional configuration.

Once the passage 40 j has been formed in the two sections 22 j and 24 jof the bone 20 j, a tubular cylindrical member 240 is inserted into thepassage 40 j and extends diametrically through the bone 20 j. Theleading end 242 of the tubular cylindrical member 240 is aligned with acircular outlet 84 j from the passage 40 j. The opposite or trailing end244 of the tubular member is aligned with a circular inlet 86 j to thepassage 40 j. The tubular member 240 has a thin cylindrical wall whichengages the sections 22 j and 24 j of the bone 201. A cylindrical innerside surface of the tubular member 240 defines a cylindrical passagehaving a diameter which is only slightly less than the diameter of thepassage 40 j.

The leading end 242 of the tubular member 240 is disposed in the compactouter layer 42 j of the bone 20 j. Similarly, the trailing end 244 ofthe tubular member 240 is disposed in the compact outer layer 42 j ofthe bone 20 j. The tubular member 240 extends across the fracture 26 jand stabilizes the two sections 22 j and 24 j of the bone 20 j. Sincethe opposite end portions of the tubular member 240 are disposed in thecompact outer layer 42 j of the bone 20 j, the tubular member is solidlysupported and holds the two sections 22 j and 24 j of the bone 20 j inalignment at the fracture 26 j.

The opposite ends 242 and 244 of the tubular member 240 are axiallyspaced from a generally cylindrical outer side surface 250 on the bone20 j. This enables the anchors 50 j and 52 j to be pressed against theouter side surface 250 of the bone 20 j. Therefore, tension forces inthe suture 38 j are transmitted through the anchors 50 j and 52 j to thebone 20 j.

By inserting the tubular member 240 into the passage 40 j, the portionsof the passage disposed on opposite sides of the fracture 26 j aremaintained in alignment. The tubular member 240 may be flexible toenable the tubular member to be inserted into a nonlinear passage 40 jthrough the bone 20 j. The tubular member 240 may be formed of metal ora polymeric material. If the tubular member 240 is formed of a polymericmaterial, it may be preferred to form the tubular member from abiodegradable or bioerodible copolymer.

In accordance with one of the features of this embodiment of theinvention, the tubular member 240 is formed of bone. By forming thetubular member 240 of bone, tissue growth into the tubular member ispromoted. The tubular member 240 may be packed with bone or bone graft.The tubular member 240 may contain bone osteoinductive protein (BMP).Bone growth inducing materials containing apatite compositions withcollagen and/or other materials may be utilized. The tubular member 240may be formed of either human or animal bone.

It is contemplated that it may be preferred to form the tubular member240 of freeze dried human bone obtained from a cadaver. The freeze driedbone will absorb body fluids. As this occurs, the tubular member 240will expand and grip the two sections 22 j and 24 j of the bone 20 j.The body fluids will be conducted into bone growth promoting materialscontained in the tubular member 240. If desired, antibiotics and/orother medicants may be provided in the bone or bone graft with which thetubular member 240 is packed. Of course, the tubular member 240 may beformed of other materials, such as biodegradable materials, if desired.

The suture 38 j is formed into a loop which extends through the openings64 j and 66 j in the anchor 50 j. At this time, the suture 38 j has alength which is substantially greater than the length illustrated inFIG. 2. The cylindrical anchor 50 j, with the suture 38 j connectedthereto, is then positioned in axial alignment with the tubular member240 which extends through the passage 40 j. Thus, the anchor 50 j ismoved to an orientation in which a longitudinal central axis of theanchor is coincident with the longitudinal central axis of thecylindrical passage 246 in the tubular member 240 which extends throughthe passage 40 j in the bone 20 j.

The leading end 58 j of the anchor 50 j is then moved into thecylindrical tubular member 240 which forms a liner for the passage 40 j.A pusher member pushes the anchor 50 j from an upper (as viewed in FIG.13) end 244 of the tubular member 240 along the passage 246 in thetubular member 240 and the passage 40 j in the bone 20 and through theoutlet 84 j from the passage. As the anchor 50 j moves through thepassages 40 j and 246, the suture 38 j is pulled through the passages bythe anchor.

The orientation of the anchor 50 j is then changed from an orientationin which the longitudinal central axis of the anchor 50 j is alignedwith the coincident longitudinal central axes of the passages 40 j and246 to an orientation in which the longitudinal central axis of theanchor 50 j extends generally perpendicular to the longitudinal centralaxis of the passages 40 j and 246, i.e., the orientation shown in FIG.13. To pivot the anchor 50 j to the orientation shown in FIG. 13, as theanchor emerges from the outlet 84, the suture 38 j is tensioned. Thecombination of the tension in the suture 38 j and force applied againstthe trailing end 60 j of the anchor 50 j by the pusher member causes theanchor to pivot about the trailing end 60 j of the anchor. The pushermember is then withdrawn and the suture 38 j tensioned to move theanchor to the position shown in FIG. 13 in a manner similar to thatdescribed in the aforementioned U.S. Pat. Nos. 5,527,343 and 5,534,012.

Although it is believed that it may be preferred to change theorientation of the anchor 50 j after it has emerged from the passages 40j and 246, the anchor could be blocked from reentering the passage inother ways if desired. Thus, the anchor could expand after emerging fromthe passages 40 j and 246. This could be accomplished by having springbiased arms held in a retracted position by engagement of spring biasedarms with the inner side surface of the tubular cylindrical member 240which lines the passage 40 j. Upon emerging from the passages 40 j and246, the arms would move outward under the influence of spring forcesand extend radially outward beyond the edge of the exit from the passage40 j. If desired, the anchor 50 j could be constructed so as to expandin a manner similar to that disclosed in U.S. Pat. Nos. 5,397,331 and/or4,409,974.

Rather than expanding under the influence of stored energy, such asspring force, the anchor 50 j could expand by absorbing body fluids.Thus, the anchor 50 j may be compressed when it moves through thepassages 40 j and 246 and will expand and absorb body fluids afteremerging from the passages 40 j and 246. It is contemplated that theanchor 50 j could be constructed so as to expand in any one of the waysdisclosed in U.S. patent application Ser. No. 08/699,553 filed Aug. 19,1996 by Peter M. Bonutti and entitled “Suture Anchor”.

Once the anchor 50 j has been moved through the passage 246, the passageis packed with bone particles and/or bone graft. The bone particlesand/or bone graft contains bone growth inducing materials. In addition,the bone particles and/or bone graft may contain medicinal substancesalong with osteoinductive protein.

The limbs 72 j and 74 j of the suture 38 j are then threaded throughopenings 64 j and 66 j in the second suture anchor 52 j. The limbs 72 jand 74 j of the suture 38 j are tensioned and the second anchor 52 j ispressed against the outer side surface 250 of the bone 20 j. While apredetermined tension force is maintained in the limbs 72 j and 74 j ofthe suture 38 j, the knot 78 j is tied in the suture to interconnect thetwo suture anchors 50 j and 52 j with the suture 38 j. The suture 38 jis then trimmed to the desired length.

Once the knot 78 j has been tied between the limbs 72 j and 74 j of thesuture 38 j, the tension in the suture 38 j presses the side surfaces 28j and 30 of the fracture 26 j together. This pressure between the sidesurfaces 28 and 30 j of the fracture 26 j is maintained by the suture 38and suture anchors 50 j and 52 j until the fracture heals. It isbelieved that it may be preferred to form the suture 38 j and sutureanchors 50 j and 52 j of a biodegradable material which, after thefracture 26 j has healed, will dissolve in the patient's body.

The cylindrical tubular member 240 which is inserted into the passage 40j through the bone 20 j performs the dual functions of lining the insideof the passage 40 j and maintaining the two sections 22 j and 24 j ofthe bone in alignment. The cylindrical tubular member 240 could have aslot formed in a side wall of the tubular member to facilitate insertionof the tubular member into the passage 40 j. It is contemplated that thecylindrical tubular member 240 could be left in the passage 40 j afterthe bone securing assembly 32 j has been installed. If the slotted orunslotted cylindrical tubular member 240 is to be left in the passage 40j, the cylindrical tubular member 240 may be formed of a biodegradableor bioerodible copolymer. When the cylindrical tubular member remains inthe passage 40 j, the suture 38 j extends through the tubular member.

Although only a knot 78 j has been shown in FIG. 13 adjacent to thesecond anchor 52 j, a suture retainer could be provided to further holdthe limbs 72 j and 74 j of the suture 38 j. If a suture retainer is tobe used in association with the knot 78 j, the suture retainer will bemoved along the limbs of the suture 38 j toward the knot before thelimbs 72 j and 74 j of the suture are trimmed to the short length shownin FIG. 13. The suture retainer would then be plastically deformed togrip the limbs 72 j and 74 j of the suture 38 j. Thereafter, the suturelimbs 72 j and 74 j would be trimmed to a desired length.

Although it is preferred to use a suture as the force transmittingmember 38 j, it should be understood that the anchors 50 j and 52 jcould be interconnected by other force transmitting members, such as arod formed of bone. Although the anchors 50 j and 52 j haveconstructions which enable them to be used with a suture, the anchorscould be constructed so as to be used with other types of forcetransmitting members. For example, the anchors 50 j and 52 j could havethread convolutions to engage thread convolutions on a forcetransmitting member formed by a rod.

In the embodiment of the invention illustrated in FIG. 13, the member240 is tubular. However, it is contemplated that a solid member could beused to transmit force to bone on opposite sides of the fracture 26 j.Thus, the member 240 could be a solid cylindrical member formed of bone.The cylindrical member may be formed of freeze dried bone.

When the member 240 is a solid member, the suture or other forcetransmitting member 38 j is eliminated. The solid member formed of bonebecomes the force transmitting member. Anchors, corresponding to theanchors 50 j and 52 j, are connected to opposite ends of the solidmember 240 formed of bone. The anchors may have internal threadconvolutions which engage external thread convolutions on the solidmember 240 formed of bone. Of course, other known connectors could beutilized to connect anchors with opposite ends of the solid member 240formed of bone.

Nonlinear Suture Passage—Tubular Member

In the embodiment of the invention illustrated in FIG. 13, the passage40 j through which the suture 38 j extends has a linear configuration.In the embodiment of the invention illustrated in FIG. 14, the passagethrough which the suture extends has a nonlinear configuration. Sincethe embodiment of the invention illustrated in FIG. 14 is generallysimilar to the embodiment of the invention illustrated in FIGS. 1-13,similar numerals will be utilized to identify similar components, thesuffix letter “k” being associated with the components of the embodimentof the invention illustrated in FIG. 14 to avoid confusion.

A bone 20 k as a fracture 26 k which divides the bone into two sections22 k and 24 k. Opposite side surfaces 28 k and 30 k of the fracture 26 kare pressed together by a bone suture assembly 32 k. The bone sutureassembly 32 k includes a suture 38 k which extends between first andsecond suture anchors 50 k and 52 k.

The suture 38 k is disposed in a passage 40 k having a nonlinearconfiguration. Thus, the passage 40 k includes a first section 140 kwhich is skewed relative to a second section 142 k of the passage 40 k.A bend 144 k is formed in the passage 40 k at an intersection 146 k ofthe first and second sections 140 k and 142 k of the passage 40 k. Theflexible suture 38 k extends around the bend 144 k along a nonlinearpath between the suture anchors 50 k and 52 k. At the bend 144 k, thesuture 38 k applies force against the section 24 k of the bone 20 kurging the section 24 k toward the left (as viewed in FIG. 5). Thisforce presses the sections 22 k and 24 k of the bone 20 k firmlytogether at the fracture 26 k.

The suture anchors 50 k and 52 k have the same cylindrical constructionas the suture anchors 50, 52, 50 j and 52 j in the embodiment of theinvention illustrated in FIGS. 2 and 13. A knot 78 k (FIG. 14) isprovided between limbs of the suture 38 k to maintain a desired tensionin the suture 38 k. This tension pulls the suture anchors 50 k and 52 ktoward each other. In addition, this tension presses the section 24 k ofthe bone 20 k firmly against the section 22 k of the bone at thefracture 26 k.

The first section 140 k of the passage 40 k is formed at an angle to andextends through a longitudinal central axis of the generally cylindricalbone 20 k. The second section 142 k of the passage 40 k is formed in adirection perpendicular, i.e., along a radius, of the generallycylindrical bone 20 k. The two sections 140 k and 142 k of the passage40 k terminate in the spongy cancellous bone tissue 44 k.

When the suture assembly 32 k is to be used to treat the fracture 26 kin the bone 20 k, the two sections 22 k and 24 k of the bone are pressedtogether at the fracture 26 k to align the side surfaces 28 k and 30 kof the fracture. A drill or other hole forming apparatus is then used toform the first section 140 k of the passage 40 k. The drill or otherhole forming apparatus is then used to form the second section 142 k ofthe passage 40 k. When the second section 142 k of the passage 40 kintersects the first section 140 k of the passage 40 k, formation of thesection 142 k of the passage 40 k is interrupted.

Once the nonlinear passage 40 k has been formed in the two sections 22 kand 24 k of the bone 20 k, a tubular cylindrical liner 240 k is insertedinto the passage 40 k. The tubular cylindrical liner 240 k is formed bytwo separate cylindrical tubular members 252 and 254 which are insertedat opposite ends of the passage 40 k. Alternatively, the tubularcylindrical liner 240 k may be formed by a single flexible tubularmember which is inserted into the section 140 k of the passage 40 k andthen moved around the bend 144 k into the section 142 k of the passage40 k.

It is believed that it may be preferred to form the tubular members 252and 254 of bone. The bone forming the tubular members 252 and 254 may beeither human or animal bone. The tubular members 252 and 254 may beformed of freeze dried human bone.

The leading end 242 k of the tubular member 252 is disposed in thecompact outer layer 42 k of the bone 20 k. Similarly, the trailing end244 k of the tubular member 254 is disposed in the compact outer layer42 k of the bone 20 k. The tubular member 252 extends across thefracture 26 k and stabilizes the two sections 22 k and 24 k of the bone20 k. Since the end portions 242 k and 244 k of the tubular members 252and 254 are disposed in the compact outer layer 42 k of the bone 20 k,the tubular members are solidly supported and hold the two sections 22 kand 24 k of the bone 20 k in alignment at the fracture 26 k.

The opposite ends 242 k and 244 k of the tubular members 252 and 254 areaxially spaced from a generally cylindrical outer side surface 250 k onthe bone 20 k. This enables the anchors 50 k and 52 k to be pressedagainst the outer side surface 250 k of the bone 20 k. Therefore,tension forces in the suture 38 k are transmitted through the anchors 50k and 52 k to the bone 20 k.

The cylindrical anchor 50 k, with the suture 38 k connected thereto, isthen positioned in axial alignment with the section 142 k of the passage40 k. The leading end 58 k of the anchor 50 k is then moved into thesection 142 k of the passage 40 k lined by the tubular member 254. Aflexible pusher member applies force against the trailing end 60 k ofthe anchor 50 k and pushes the anchor around the bend 144 k and throughthe section 140 k of the passage 40 k lined by the tubular member 252.

Alternatively, a flexible wire or other member could be inserted intothe section 140 k of the passage 40 k. The wire would move around thebend 144 k and extend outward from the section 142 k of the passage. Thewire would then be connected with the anchor 50 k and suture 38 k. Theleading end 58 k of the anchor 50 k would then be inserted into thesection 142 k of the passage 40 k. Tension on the wire would pull theanchor 50 k around the bend 144 k and out of the section 140 k of thepassage 40 k.

The passages in the tubular members 252 and 254 may be packed with boneparticles and/or bone graft. Bone osteoinductive protein (BMP) may beprovided in the tubular members. Antibiotics and/or other medicants maybe included along with collagen.

The suture 38 k is then threaded through openings in the suture anchor52 k. The suture 38 k is then tensioned and the second anchor 52 k ispressed against the outer side surface of the bone 20 k. While apredetermined tension force is maintained in the suture 38 k, the knot78 k is tied.

In the illustrated embodiment of the invention, the two sections 140 kand 142 k of the passage 40 k have a straight cylindrical configuration.However, it is contemplated that the sections 140 k and 142 k of thepassage 40 k could have a different configuration if desired. Forexample, the section 140 k and/or 142 k of the passage 40 k could have anonlinear central axis and could have a noncircular cross-sectionalconfiguration of desired.

Body tissue, corresponding to the body tissue 132 of FIG. 4 could bedisposed between the anchor 50 k and/or 52 k and the bone 20 k. Althoughthe suture 38 k has been illustrated as having a pair of limbs orsections which extend between the anchors 50 k and 52 k, the suture 38 kcould have a single limb or section if desired. The anchor 50 c couldmechanically expand, by absorbing body liquid or under the influence ofexpansion springs, after the anchor has emerged from the passage 40 k toprevent the anchor from being pulled back through the passage.

Retainer and Tubular Member

In the embodiment of the invention illustrated in FIG. 13, a pair ofsuture anchors 50 j and 52 j are connected with the suture 38 j tomaintain tension in the suture and pressure against opposite sidesurfaces 28 j and 30 j of the fracture 26 j. In the embodiment of theinvention illustrated in FIG. 15, a suture retainer is used in place ofone of the suture anchors. Since the embodiment of the inventionillustrated in FIG. 15 is generally similar to the embodiment of theinvention illustrated in FIG. 13, similar numerals will be utilized todesignate similar components, the suffix letter “m” being associatedwith the embodiment of the invention illustrated in FIG. 15 to avoidconfusion.

A bone 20 m has sections 22 m and 24 m which are separated by a fracture26 m. The fracture 26 m has side surfaces 28 m and 30 m which arepressed together by a bone suture assembly 32 m. A suture 38 m extendsthrough a cylindrical passage 40 m which extends diametrically throughthe generally cylindrical bone 20 m. The suture 38 m has a pair of limbsor sections 72 m and 74 m which are connected with a suture anchor 50 m.The suture anchor 50 m has the same construction as the suture anchor 50of FIG. 2.

Once the passage 40 has been formed in the two tubular sections 22 m and24 m of the bone 20 m, a tubular cylindrical member 240 m is installedinto the passage 40 m and extends diametrically through the bone 20 m.The leading end 242 m of the cylindrical member 240 m is aligned with acircular outlet 84 m from the passage 40 m. The opposite or trailing end244 m of the tubular member 240 m is aligned with a circular inlet 86 mto the passage 40 m.

The tubular member 240 m has a thin cylindrical wall which engages thesections 22 m and 24 m of the bone 20 m. A cylindrical inner sidesurface of the tubular member 240 m defines a cylindrical passage 246 mhaving a diameter which is only slightly less than the diameter of thepassage 40 m. The tubular member 240 m is formed of bone. Alternatively,the tubular member 240 m could be formed of a biodegradable material.

The leading end 242 m of the tubular member 240 m is disposed in thecompact outer layer 42 m of the bone 20 m. Similarly, the trailing end244 m of the tubular member 240 m is disposed in the compact outer layer42 m of the bone 20 m. The tubular member 240 m extends across thefracture 26 m and stabilizes the two sections 22 m and 24 m of the bone20 m. Since the opposite end portions of the tubular member 240 m aredisposed in the compact outer layer 42 m of the bone 20 m, the tubularmember is solidly supported and holds the two sections 22 m and 24 m ofthe bone 20 m in alignment at the fracture 26 m.

The opposite ends 242 m and 244 m of the tubular member 240 m areaxially spaced from a generally cylindrical outer side surface 250 m onthe bone 20 m. This enables the anchors 50 m and 92 m to be pressedagainst the outer side surface 250 m of the bone 20 m. Therefore,tension forces in the suture 38 m are transmitted through the anchors 50m and 92 m to the bone 20 m.

The tubular member 240 m is formed of freeze dried human bone. Thetubular member 240 m is packed with bone and/or bone graft. The tubularmember 240 m also contains bone osteoinductive protein (BMP). Suitablemedicants may be provided in the tubular member 240 m.

A suture retainer 92 m is used in place of the suture anchor 52 of FIG.2. The suture retainer 92 m (FIG. 15) has a spherical configuration. Acylindrical passage 94 m extends through the center of the sphericalsuture retainer 92 m. The sections 72 m and 74 m of the suture 38 mextend around the spherical outer side surface of the suture retainer 92m. Thus, a loop is formed in each of the sections 72 m and 74 m aroundportions of the suture retainer 92 m.

If desired, the suture retainer 92 m could have a differentconfiguration. For example, the suture retainer 92 m could have an ovalor elliptical configuration. Although the passage 94 m has a linearcentral axis, the passage could have a nonlinear central axis. Ifdesired, a plurality of passages having the same or differentconfigurations could be provided in the suture retainer 92 m.

After the suture 38 m has been inserted through the suture retainer 92m, the suture retainer 92 m is moved along the sections 72 m and 74 m ofthe suture 38 m toward the bone 20 m. The suture retainer 92 m is formedas one piece of a polymeric material having a relatively low coefficientfriction. Therefore, the two sections 72 m and 74 m of the suture 30 mcan readily slide along the surfaces of the suture retainer 52 m whilethe suture retainer moves toward the bone 20 m.

A predetermined tension is maintained in the sections 72 m and 74 m ofthe suture 38 m while the suture retainer 92 m is pressed against thebone 20 m. This results in the suture 38 m being pulled tightly againstthe suture anchor 50 m. The tension in the suture 38 m is effective topress the suture anchor 50 m and retainer 92 m against opposite sides ofthe bone 20 m with a predetermined force.

While the sections 72 m and 74 m of the suture 38 m are being tensionedwith a predetermined force, the suture retainer 92 m is plasticallydeformed in the same manner as previously described in conjunction withthe embodiment of the invention illustrated in FIG. 3. To plasticallydeform the suture retainer 92 m, a plurality of force applying or clampmembers are pressed against the suture retainer with a predeterminedminimum force. The force applied against the suture retainer 92 m by theforce applying members is sufficient to cause plastic deformation of thematerial of the suture retainer.

The force is applied against the suture retainer 92 m while the sutureretainer is at a temperature which is below the transition temperatureof the biodegradable polymer which forms the suture retainer 92 m. Thus,the suture retainer 92 m is at approximately the same temperature as thebone 20 m when the force is applied against the suture retainer. Theforce causes the material of the suture retainer 92 m to flow and gripthe sections 72 m and 74 m of the suture 38 m.

The suture retainer 92 m may be formed of many different materials.However, it is believed that it will be preferred to form the sutureretainer 92 m of a biodegradable polymer. One biodegradable polymerwhich may be utilized is polycaperlactone. Alternatively, the sutureretainer 92 m could be formed of polyethylene oxide terephthalate orpolybutylene terephthalate. It is also contemplated that otherbiodegradable or bioerodible copolymers could be utilized.

Although it is preferred to form the suture retainer 92 m of abiodegradable material, the suture retainer could be formed of amaterial which is not biodegradable. For example, the suture retainer 92m could be formed of an acetyl resin, such as “DELRIN” (trademark).Alternatively, the suture retainer 92 m could be formed ofpara-dimethylamino-benzenediaz-o sodium sulfonate, such as “DEXON”(trademark). The construction of the suture retainer 92 m and the mannerin which is cooperates with the suture 38 m is the same as is disclosedin U.S. patent application Ser. No. 08/905,084 filed Aug. 1, 1997 byPeter M. Bonutti et al. and entitled “Method and Apparatus for Securinga Suture”.

The suture retainer 92 m is plastically deformed to grip the limbs 72 mand 74 m of the suture 38 m. However, the suture retainer 92 m could beconstructed so as to be mechanically actuated to grip the suture 38 m.If desired, a combination of a mechanical gripping action and plasticdeformation could be utilized by a retainer to grip the suture 38 m.

Conclusion

In view of the foregoing description, it is apparent that the presentinvention relates to a method of securing sections 22 and 24 of afractured bone 20. Sections 22 and 24 of a fractured bone 20 are heldagainst movement relative to each other by a force transmitting member,such as a suture 38, which extends through a passage 40 in the bone. Thepassage 40 in the bone may have a linear or nonlinear configuration.Tension is maintained in the force transmitting member 38 to presssurfaces 28 and 30 on the fracture together by securing anchors 50 and52 or suture retainers 92 to opposite ends of the force transmittingmember 38. It is believed that a suture 38 may advantageously be used asthe force transmitting member.

A tubular member 240 is positioned in a linear passage (FIGS. 13 and 15)or a nonlinear passage (FIG. 14) through the bone 20. The tubular member240 extends into portions of the passage 40 on opposite sides of thefracture 26. End portions of the tubular member may be positioned in acompact outer layer 42 of the bone. The tubular member 240 may be formedof bone. The force transmitting member 38 may be formed of bone or otherbody tissue.

1. A bone suture assembly for treating a fracture of a bone comprising:a first rigid bone plate positionable proximate to the bone; a secondrigid bone plate positionable proximate to the bone generally oppositethe first bone plate; a suture connected with the first and second rigidbone plates to thereby stabilize the fracture, the suture positionablethrough a passage in the bone; and at least one fastener positionablethrough the first rigid bone plate into the bone to hold the first rigidbone plate to the bone.
 2. A bone suture assembly as defined in claim 1wherein the passage is nonlinear.
 3. A bone suture assembly as definedin claim 2 wherein at least one tubular member is disposed within thenonlinear passage and wherein the suture is disposed within at least onetubular member.
 4. A bone suture assembly as defined in claim 1 whereinthe suture is positionable through the fracture.
 5. A bone sutureassembly as defined in claim 1 wherein the suture is positionablethrough the fracture.
 6. A bone suture assembly as defined in claim 1wherein at least one of the bone plates includes a channel extendingbetween a bone-contacting surface of the plate and a non-bone-contactingsurface of the plate, and wherein the suture is positioned in thechannel.
 7. A bone suture assembly as defined in claim 6 wherein thesurfaces face in generally opposite directions.
 8. A bone sutureassembly for treating a fracture of a bone comprising: a first boneplate positionable proximate to the bone; a suture positionable throughthe first bone plate and across the fracture of the bone to therebystabilize the fracture; and a tubular member positionable in the bonethrough the fracture, generally orthogonal to the first bone plate,wherein the tubular member remains in the bone such that the suture isdisposed within the tubular member.
 9. A bone suture assembly as definedin claim 8 wherein the tubular member is packed with bone particles. 10.A bone suture assembly as defined in claim 8 wherein the tubular memberis packed with bone osteoinductive protein.
 11. A bone suture assemblyfor treating a fracture of a bone comprising: a first suture anchorpositionable proximate to the bone; a rigid bone plate positionablebetween the first suture anchor and the bone, the rigid bone plate andfirst suture anchor positionable generally on the same side of the bone;a suture extending through the rigid bone plate and connected with thefirst suture anchor, the suture positionable across the bone to therebystabilize the fracture; and at least one fastener positionable throughthe rigid bone plate into the bone to hold the rigid bone plate to thebone.
 12. A bone suture assembly as defined in claim 11 furtherincluding a second suture anchor positionable at a location spaced fromthe first suture anchor, the second suture anchor connected with thesuture.
 13. A bone suture assembly as defined in claim 12 furtherincluding a passage through bone located between the first and secondsuture anchors, wherein the suture is disposed within the passage.
 14. Abone suture assembly as defined in claim 12 wherein at least onefastener extends across the fracture of the bone.
 15. A bone sutureassembly as defined in claim 12 wherein the at least one fastenerincludes a screw.
 16. A bone suture assembly as defined in claim 12wherein the first and second suture anchors are suture retainers.
 17. Abone suture assembly as defined in claim 16 wherein the suture retainersinclude deformable material to hold the suture retainers to the suture.18. A bone suture assembly as defined in claim 12 wherein the sutureincludes a plurality of generally parallel suture sections.
 19. A methodfor treating a fracture of a bone comprising: forming at least onepassage through the bone, where the passage traverses the fracture;positioning at least one suture anchor proximate to the bone;positioning at least one bone plate between the at least one sutureanchor and the bone; fastening the at least one bone plate to the bonewith at least one screw; moving at least one suture through the passagein the bone and through at least one bone plate; attaching at least onesuture to at least one suture anchor; and tensioning at least one sutureto stabilize the fracture of the bone.
 20. A method as defined in claim19 wherein at least one suture anchor is a suture retainer.
 21. A methodas defined in claim 19 wherein at least one screw has a length less thana diameter of the bone.
 22. A method as defined in claim 19 wherein atleast one screw has a length greater than a diameter of the bone.
 23. Amethod as defined in claim 22 wherein at least one screw includes atleast one nut.
 24. A method as defined in claim 23 wherein at least onescrew extends across the fracture of the bone.
 25. A method as definedin claim 19 wherein attaching at least one suture to at least one sutureanchor is performed prior to moving at least one suture, and whereinmoving at least one suture includes moving at least one suture attachedto at least one suture anchor through at least one passage.
 26. A methodas defined in claim 25 further including changing the orientation of atleast one suture anchor from a first to a second configuration therebycausing at least one suture anchor to become proximate to the bone andimpassable through at least one passage.
 27. A method as defined inclaim 26 wherein tensioning at least one suture includes tensioning atleast one suture between at least two suture anchors to stabilize thefracture of the bone.